import java.util.ArrayList;
import java.util.List;

/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: fzykd
 * Date: 2023-03-04
 * Time: 12:49
 */

public class TestDemo {
    public static void main(String[] args) {
        List list = new ArrayList();
        list.add(0,10); //前面的元素不能是空
        System.out.println(list);}
}
